About a month ago my check engine light came on. Car was running fine so took it to my regular mechanic (not the dealer) and they read the code and replaced a smog part (not sure which one). Light came back on yesterday so I took it back. Mechanic checks it and says the part he replaced is fine. Says he needs to drop the gas tank as it could be a vapor issue and needs to check that out. Car has never idled rough or had any issues at all. Runs great. Any feedback on the gas tank issue or any issues withe the check engine light?

 

Need the code/codes that were thrown. And need to know what part he replaced. And I'm already thinking you need to find another mechanic...

 

OP: the code reader will put out a letter and 4-digit code like P1234; the code from your car's OBD port identifies the problematic part or narrows it down.
That code should tell us(and any mechanic or car tech) a lot.

Did your mechanic replace an oxygen sensor, by chance?

 

Oxygen sensor was the problem. All good now. Thanks for the feedback